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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
	dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
	bobby.prani@gmail.com, Boqun Feng <boqun.feng@gmail.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 06/14] torture: Stop onoff task if there is only one cpu
Date: Wed, 15 Jun 2016 15:09:35 -0700	[thread overview]
Message-ID: <1466028583-8780-6-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160615220924.GA7877@linux.vnet.ibm.com>

From: Boqun Feng <boqun.feng@gmail.com>

If the whole system has only one cpu, that cpu won't be able to be
offlined, so there is no need onoff task is stil running.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/torture.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/kernel/torture.c b/kernel/torture.c
index fb39a06bbef5..75961b3decfe 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -194,6 +194,12 @@ torture_onoff(void *arg)
 	for_each_online_cpu(cpu)
 		maxcpu = cpu;
 	WARN_ON(maxcpu < 0);
+
+	if (maxcpu == 0) {
+		VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
+		goto stop;
+	}
+
 	if (onoff_holdoff > 0) {
 		VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
 		schedule_timeout_interruptible(onoff_holdoff);
@@ -209,6 +215,8 @@ torture_onoff(void *arg)
 				       &sum_online, &min_online, &max_online);
 		schedule_timeout_interruptible(onoff_interval);
 	}
+
+stop:
 	torture_kthread_stopping("torture_onoff");
 	return 0;
 }
-- 
2.5.2

  parent reply	other threads:[~2016-06-15 22:10 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-15 22:09 [PATCH tip/core/rcu 0/14] Torture-test changes for 4.8 Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 01/14] torture: Simplify code, eliminate RCU_PERF_TEST_RUNNABLE Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 02/14] torture: Remove CONFIG_RCU_TORTURE_TEST_RUNNABLE, simplify code Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 03/14] torture: Forgive lengthy trace dumps and preemption Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 04/14] torture: Break online and offline functions out of torture_onoff() Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 05/14] torture: Add starvation events to error summary Paul E. McKenney
2016-06-15 22:09 ` Paul E. McKenney [this message]
2016-06-15 22:09 ` [PATCH tip/core/rcu 07/14] rcutorture/doc: Create initrd using dracut Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 08/14] rcutorture: Use vmlinux as the fallback kernel image Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 09/14] rcutorture: Make -soundhw a x86 specific option Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 10/14] rcutorture: Don't specify the cpu type of QEMU on PPC Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 11/14] rcutorture: Drop "-soundhw pcspkr" from x86 boot arguments Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 12/14] rcuperf: Don't treat gp_exp mis-setting as a WARN Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 13/14] torture: Inflict default jitter Paul E. McKenney
2016-06-15 22:09 ` [PATCH tip/core/rcu 14/14] rcutorture: Fix error return code in rcu_perf_init() Paul E. McKenney

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